[React 18] Strict Mode issues punch list

[cee-chen]

All links below point to local dev - these issues do not appear to occur on staging.

• EuiToolTip - no tooltips work anywhere across the site
• EuiResizeObserver - the first example on the page always shows 0, 0, the second example works
  • Related: EuiAccordion dynamic height changes also does not work (due to resize observer not working)
• EuiMutationObserver - does not work whatsoever
• EuiDelay - EuiDelayRender works, EuiDelayHide does not
• EuiDataGrid - all datagrid cell popovers on all examples flash briefly and then disappear
• EuiBasicTable - page errors on local but not on staging
  

[JasonStoltz]

Bumping this down in priority, because neither we nor Kibana use Strict Mode currently.